http://www.hbdinc.ca/
I had these guys do a similar crack that was leaking pretty badly. They injected poly grout from the inside, so no digging of the yard. I only lived with it for one melt season after that (moved), but the leak stopped at least for that one season. Can't recall the warranty details, as I discarded the info after moving.
That method is probably ok for an unfinished space, but I don't think I'd ever trust it enough to finish over top of that kind of repair.
2 Cents; no charge.